If you feel like removing a tank, it would be very easy. You would need to drill a hole in the fuse side at the site where the false bulkhead is (sorry, don't remember a part number). it is the fuse former that is just forward of F604. It is a likely area were you can run the pressure lines down from your panel.
With the tank off, run the lines infront of the spar until you get out to the leading edge out board of the tank. Then fish them through one of the lighening holes in the spar web toward the area of the aileron access plate. I mounted my probe on the access plate with no trouble.
As I said, the biggest pain is taking off a tank. Not sure if you could fish a wire from the access hole toward the fuse on the front of the spar and pull the pressure lines through. Would be tough, but perhaps worth a try. Trouble is they would not be supported.
Regards,